1. Field of the Invention
This invention relates to a ladder, more particularly to a retractable ladder.
2. Description of the Related Art
A ladder is commonly used for retrieving an article that is stored in a high place or for repairing something that is positioned at a substantial height. A conventional ladder mainly includes two spaced-apart upright rods, and a plurality of spaced-apart cross plates fixed between the upright rods. Although this kind of ladder can achieve its intended purpose, it cannot be folded for storage, so that the conventional ladder is either leant vertically on a wall or is placed horizontally on the ground, thereby occupying a substantial space when not in use. Further, people passing by the conventional ladder may easily trip over the ladder and get injured. Moreover, because the conventional ladder is long and is not retractable, it cannot be placed inside a trunk or passenger compartment of a car. Hence, the conventional ladder is very inconvenient to store, transport, and carry. Additionally, since the conventional ladder is not retractable, the user must purchase ladders of different heights so as to be prepared for various height circumstances.